Microelectro-mechanical systems (MEMS) are used for miniaturized apparatuses and assembly groups, which are realized within very small dimensions and which comprise components which cooperate with each other towards a specific functionality. Typically, a MEMS consists of one or more sensors or actuators and an electronic control circuit which are all realized on a common semiconductor substrate. The size of the entire MEMS is typically in the order of a few micrometers. MEMS may be used for any type of application which requires a mechanical interaction between (a) a mechanical component, e.g. a mechanical sensor or an actuator, and (b) an electronic circuit connected thereto.
Generally speaking, MEMS are electromechanical structures which are built up by standard semiconductor processes. Due to the large importance of MEMS in many applications MEMS-specific equipment and processes have been developed in order to optimize the cost and the performance of MEMS devices. For that reason, the main substrate for modem MEMS devices is Si, as it is a common and easy-to-process material. However, in the wide field of MEMS also other materials are known to be used such as SiC, diamond, or quartz. A good choice for a proper material may depend on temperature requirements or intrinsic material properties.